mention other ways than add-hook also

[Dan Jacobson <jidanni@jidanni.org>]

In the manual, after all the setq hook examples were changed to
add-hook examples, users end up with miles long hooks as they adjust
their hooks without starting a new emacs.  So put back a few setq hook
examples, or mention how to do eval-last-sexp in .emacs without ending
up with miles long hooks, failed stuff all appended for the ride.

K> add-hook's doc string clearly states that the HOOK symbol is a
K> variable, from which you can infer that you can modify it with
K> set/setq like any other.

"Infer" perhaps, but lower powered users like to follow examples.
Users might even think they must restart emacs every time they change
a hook.

K> The reason users should not be encouraged to do so is obvious: a
K> hook is a list-valued variable that should be modified
K> incrementally to limit the scope of the change to what is intended
K> and not not affect other aspects of the system of which the user
K> may not be aware.

OK, but it's just like if one is not told how to change $PATH, only
how to prepend/append to $PATH.  Works, but no cigar.